3441b159e3061f68c043c34a250aadf77a020081
[deliverable/linux.git] / drivers / target / target_core_transport.c
1 /*******************************************************************************
2 * Filename: target_core_transport.c
3 *
4 * This file contains the Generic Target Engine Core.
5 *
6 * (c) Copyright 2002-2013 Datera, Inc.
7 *
8 * Nicholas A. Bellinger <nab@kernel.org>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 *
24 ******************************************************************************/
25
26 #include <linux/net.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/kthread.h>
33 #include <linux/in.h>
34 #include <linux/cdrom.h>
35 #include <linux/module.h>
36 #include <linux/ratelimit.h>
37 #include <linux/vmalloc.h>
38 #include <asm/unaligned.h>
39 #include <net/sock.h>
40 #include <net/tcp.h>
41 #include <scsi/scsi_proto.h>
42 #include <scsi/scsi_common.h>
43
44 #include <target/target_core_base.h>
45 #include <target/target_core_backend.h>
46 #include <target/target_core_fabric.h>
47
48 #include "target_core_internal.h"
49 #include "target_core_alua.h"
50 #include "target_core_pr.h"
51 #include "target_core_ua.h"
52
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/target.h>
55
56 static struct workqueue_struct *target_completion_wq;
57 static struct kmem_cache *se_sess_cache;
58 struct kmem_cache *se_ua_cache;
59 struct kmem_cache *t10_pr_reg_cache;
60 struct kmem_cache *t10_alua_lu_gp_cache;
61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
63 struct kmem_cache *t10_alua_lba_map_cache;
64 struct kmem_cache *t10_alua_lba_map_mem_cache;
65
66 static void transport_complete_task_attr(struct se_cmd *cmd);
67 static void transport_handle_queue_full(struct se_cmd *cmd,
68 struct se_device *dev);
69 static int transport_put_cmd(struct se_cmd *cmd);
70 static void target_complete_ok_work(struct work_struct *work);
71
72 int init_se_kmem_caches(void)
73 {
74 se_sess_cache = kmem_cache_create("se_sess_cache",
75 sizeof(struct se_session), __alignof__(struct se_session),
76 0, NULL);
77 if (!se_sess_cache) {
78 pr_err("kmem_cache_create() for struct se_session"
79 " failed\n");
80 goto out;
81 }
82 se_ua_cache = kmem_cache_create("se_ua_cache",
83 sizeof(struct se_ua), __alignof__(struct se_ua),
84 0, NULL);
85 if (!se_ua_cache) {
86 pr_err("kmem_cache_create() for struct se_ua failed\n");
87 goto out_free_sess_cache;
88 }
89 t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
90 sizeof(struct t10_pr_registration),
91 __alignof__(struct t10_pr_registration), 0, NULL);
92 if (!t10_pr_reg_cache) {
93 pr_err("kmem_cache_create() for struct t10_pr_registration"
94 " failed\n");
95 goto out_free_ua_cache;
96 }
97 t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
98 sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
99 0, NULL);
100 if (!t10_alua_lu_gp_cache) {
101 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
102 " failed\n");
103 goto out_free_pr_reg_cache;
104 }
105 t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
106 sizeof(struct t10_alua_lu_gp_member),
107 __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
108 if (!t10_alua_lu_gp_mem_cache) {
109 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
110 "cache failed\n");
111 goto out_free_lu_gp_cache;
112 }
113 t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
114 sizeof(struct t10_alua_tg_pt_gp),
115 __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
116 if (!t10_alua_tg_pt_gp_cache) {
117 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
118 "cache failed\n");
119 goto out_free_lu_gp_mem_cache;
120 }
121 t10_alua_lba_map_cache = kmem_cache_create(
122 "t10_alua_lba_map_cache",
123 sizeof(struct t10_alua_lba_map),
124 __alignof__(struct t10_alua_lba_map), 0, NULL);
125 if (!t10_alua_lba_map_cache) {
126 pr_err("kmem_cache_create() for t10_alua_lba_map_"
127 "cache failed\n");
128 goto out_free_tg_pt_gp_cache;
129 }
130 t10_alua_lba_map_mem_cache = kmem_cache_create(
131 "t10_alua_lba_map_mem_cache",
132 sizeof(struct t10_alua_lba_map_member),
133 __alignof__(struct t10_alua_lba_map_member), 0, NULL);
134 if (!t10_alua_lba_map_mem_cache) {
135 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
136 "cache failed\n");
137 goto out_free_lba_map_cache;
138 }
139
140 target_completion_wq = alloc_workqueue("target_completion",
141 WQ_MEM_RECLAIM, 0);
142 if (!target_completion_wq)
143 goto out_free_lba_map_mem_cache;
144
145 return 0;
146
147 out_free_lba_map_mem_cache:
148 kmem_cache_destroy(t10_alua_lba_map_mem_cache);
149 out_free_lba_map_cache:
150 kmem_cache_destroy(t10_alua_lba_map_cache);
151 out_free_tg_pt_gp_cache:
152 kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
153 out_free_lu_gp_mem_cache:
154 kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
155 out_free_lu_gp_cache:
156 kmem_cache_destroy(t10_alua_lu_gp_cache);
157 out_free_pr_reg_cache:
158 kmem_cache_destroy(t10_pr_reg_cache);
159 out_free_ua_cache:
160 kmem_cache_destroy(se_ua_cache);
161 out_free_sess_cache:
162 kmem_cache_destroy(se_sess_cache);
163 out:
164 return -ENOMEM;
165 }
166
167 void release_se_kmem_caches(void)
168 {
169 destroy_workqueue(target_completion_wq);
170 kmem_cache_destroy(se_sess_cache);
171 kmem_cache_destroy(se_ua_cache);
172 kmem_cache_destroy(t10_pr_reg_cache);
173 kmem_cache_destroy(t10_alua_lu_gp_cache);
174 kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
175 kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
176 kmem_cache_destroy(t10_alua_lba_map_cache);
177 kmem_cache_destroy(t10_alua_lba_map_mem_cache);
178 }
179
180 /* This code ensures unique mib indexes are handed out. */
181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
183
184 /*
185 * Allocate a new row index for the entry type specified
186 */
187 u32 scsi_get_new_index(scsi_index_t type)
188 {
189 u32 new_index;
190
191 BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
192
193 spin_lock(&scsi_mib_index_lock);
194 new_index = ++scsi_mib_index[type];
195 spin_unlock(&scsi_mib_index_lock);
196
197 return new_index;
198 }
199
200 void transport_subsystem_check_init(void)
201 {
202 int ret;
203 static int sub_api_initialized;
204
205 if (sub_api_initialized)
206 return;
207
208 ret = request_module("target_core_iblock");
209 if (ret != 0)
210 pr_err("Unable to load target_core_iblock\n");
211
212 ret = request_module("target_core_file");
213 if (ret != 0)
214 pr_err("Unable to load target_core_file\n");
215
216 ret = request_module("target_core_pscsi");
217 if (ret != 0)
218 pr_err("Unable to load target_core_pscsi\n");
219
220 ret = request_module("target_core_user");
221 if (ret != 0)
222 pr_err("Unable to load target_core_user\n");
223
224 sub_api_initialized = 1;
225 }
226
227 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
228 {
229 struct se_session *se_sess;
230
231 se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
232 if (!se_sess) {
233 pr_err("Unable to allocate struct se_session from"
234 " se_sess_cache\n");
235 return ERR_PTR(-ENOMEM);
236 }
237 INIT_LIST_HEAD(&se_sess->sess_list);
238 INIT_LIST_HEAD(&se_sess->sess_acl_list);
239 INIT_LIST_HEAD(&se_sess->sess_cmd_list);
240 INIT_LIST_HEAD(&se_sess->sess_wait_list);
241 spin_lock_init(&se_sess->sess_cmd_lock);
242 kref_init(&se_sess->sess_kref);
243 se_sess->sup_prot_ops = sup_prot_ops;
244
245 return se_sess;
246 }
247 EXPORT_SYMBOL(transport_init_session);
248
249 int transport_alloc_session_tags(struct se_session *se_sess,
250 unsigned int tag_num, unsigned int tag_size)
251 {
252 int rc;
253
254 se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
255 GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
256 if (!se_sess->sess_cmd_map) {
257 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
258 if (!se_sess->sess_cmd_map) {
259 pr_err("Unable to allocate se_sess->sess_cmd_map\n");
260 return -ENOMEM;
261 }
262 }
263
264 rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
265 if (rc < 0) {
266 pr_err("Unable to init se_sess->sess_tag_pool,"
267 " tag_num: %u\n", tag_num);
268 kvfree(se_sess->sess_cmd_map);
269 se_sess->sess_cmd_map = NULL;
270 return -ENOMEM;
271 }
272
273 return 0;
274 }
275 EXPORT_SYMBOL(transport_alloc_session_tags);
276
277 struct se_session *transport_init_session_tags(unsigned int tag_num,
278 unsigned int tag_size,
279 enum target_prot_op sup_prot_ops)
280 {
281 struct se_session *se_sess;
282 int rc;
283
284 se_sess = transport_init_session(sup_prot_ops);
285 if (IS_ERR(se_sess))
286 return se_sess;
287
288 rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
289 if (rc < 0) {
290 transport_free_session(se_sess);
291 return ERR_PTR(-ENOMEM);
292 }
293
294 return se_sess;
295 }
296 EXPORT_SYMBOL(transport_init_session_tags);
297
298 /*
299 * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
300 */
301 void __transport_register_session(
302 struct se_portal_group *se_tpg,
303 struct se_node_acl *se_nacl,
304 struct se_session *se_sess,
305 void *fabric_sess_ptr)
306 {
307 const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
308 unsigned char buf[PR_REG_ISID_LEN];
309
310 se_sess->se_tpg = se_tpg;
311 se_sess->fabric_sess_ptr = fabric_sess_ptr;
312 /*
313 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
314 *
315 * Only set for struct se_session's that will actually be moving I/O.
316 * eg: *NOT* discovery sessions.
317 */
318 if (se_nacl) {
319 /*
320 *
321 * Determine if fabric allows for T10-PI feature bits exposed to
322 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
323 *
324 * If so, then always save prot_type on a per se_node_acl node
325 * basis and re-instate the previous sess_prot_type to avoid
326 * disabling PI from below any previously initiator side
327 * registered LUNs.
328 */
329 if (se_nacl->saved_prot_type)
330 se_sess->sess_prot_type = se_nacl->saved_prot_type;
331 else if (tfo->tpg_check_prot_fabric_only)
332 se_sess->sess_prot_type = se_nacl->saved_prot_type =
333 tfo->tpg_check_prot_fabric_only(se_tpg);
334 /*
335 * If the fabric module supports an ISID based TransportID,
336 * save this value in binary from the fabric I_T Nexus now.
337 */
338 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
339 memset(&buf[0], 0, PR_REG_ISID_LEN);
340 se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
341 &buf[0], PR_REG_ISID_LEN);
342 se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
343 }
344
345 spin_lock_irq(&se_nacl->nacl_sess_lock);
346 /*
347 * The se_nacl->nacl_sess pointer will be set to the
348 * last active I_T Nexus for each struct se_node_acl.
349 */
350 se_nacl->nacl_sess = se_sess;
351
352 list_add_tail(&se_sess->sess_acl_list,
353 &se_nacl->acl_sess_list);
354 spin_unlock_irq(&se_nacl->nacl_sess_lock);
355 }
356 list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
357
358 pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
359 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
360 }
361 EXPORT_SYMBOL(__transport_register_session);
362
363 void transport_register_session(
364 struct se_portal_group *se_tpg,
365 struct se_node_acl *se_nacl,
366 struct se_session *se_sess,
367 void *fabric_sess_ptr)
368 {
369 unsigned long flags;
370
371 spin_lock_irqsave(&se_tpg->session_lock, flags);
372 __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
373 spin_unlock_irqrestore(&se_tpg->session_lock, flags);
374 }
375 EXPORT_SYMBOL(transport_register_session);
376
377 static void target_release_session(struct kref *kref)
378 {
379 struct se_session *se_sess = container_of(kref,
380 struct se_session, sess_kref);
381 struct se_portal_group *se_tpg = se_sess->se_tpg;
382
383 se_tpg->se_tpg_tfo->close_session(se_sess);
384 }
385
386 int target_get_session(struct se_session *se_sess)
387 {
388 return kref_get_unless_zero(&se_sess->sess_kref);
389 }
390 EXPORT_SYMBOL(target_get_session);
391
392 void target_put_session(struct se_session *se_sess)
393 {
394 kref_put(&se_sess->sess_kref, target_release_session);
395 }
396 EXPORT_SYMBOL(target_put_session);
397
398 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
399 {
400 struct se_session *se_sess;
401 ssize_t len = 0;
402
403 spin_lock_bh(&se_tpg->session_lock);
404 list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
405 if (!se_sess->se_node_acl)
406 continue;
407 if (!se_sess->se_node_acl->dynamic_node_acl)
408 continue;
409 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
410 break;
411
412 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
413 se_sess->se_node_acl->initiatorname);
414 len += 1; /* Include NULL terminator */
415 }
416 spin_unlock_bh(&se_tpg->session_lock);
417
418 return len;
419 }
420 EXPORT_SYMBOL(target_show_dynamic_sessions);
421
422 static void target_complete_nacl(struct kref *kref)
423 {
424 struct se_node_acl *nacl = container_of(kref,
425 struct se_node_acl, acl_kref);
426
427 complete(&nacl->acl_free_comp);
428 }
429
430 void target_put_nacl(struct se_node_acl *nacl)
431 {
432 kref_put(&nacl->acl_kref, target_complete_nacl);
433 }
434 EXPORT_SYMBOL(target_put_nacl);
435
436 void transport_deregister_session_configfs(struct se_session *se_sess)
437 {
438 struct se_node_acl *se_nacl;
439 unsigned long flags;
440 /*
441 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
442 */
443 se_nacl = se_sess->se_node_acl;
444 if (se_nacl) {
445 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
446 if (se_nacl->acl_stop == 0)
447 list_del(&se_sess->sess_acl_list);
448 /*
449 * If the session list is empty, then clear the pointer.
450 * Otherwise, set the struct se_session pointer from the tail
451 * element of the per struct se_node_acl active session list.
452 */
453 if (list_empty(&se_nacl->acl_sess_list))
454 se_nacl->nacl_sess = NULL;
455 else {
456 se_nacl->nacl_sess = container_of(
457 se_nacl->acl_sess_list.prev,
458 struct se_session, sess_acl_list);
459 }
460 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
461 }
462 }
463 EXPORT_SYMBOL(transport_deregister_session_configfs);
464
465 void transport_free_session(struct se_session *se_sess)
466 {
467 struct se_node_acl *se_nacl = se_sess->se_node_acl;
468 /*
469 * Drop the se_node_acl->nacl_kref obtained from within
470 * core_tpg_get_initiator_node_acl().
471 */
472 if (se_nacl) {
473 se_sess->se_node_acl = NULL;
474 target_put_nacl(se_nacl);
475 }
476 if (se_sess->sess_cmd_map) {
477 percpu_ida_destroy(&se_sess->sess_tag_pool);
478 kvfree(se_sess->sess_cmd_map);
479 }
480 kmem_cache_free(se_sess_cache, se_sess);
481 }
482 EXPORT_SYMBOL(transport_free_session);
483
484 void transport_deregister_session(struct se_session *se_sess)
485 {
486 struct se_portal_group *se_tpg = se_sess->se_tpg;
487 const struct target_core_fabric_ops *se_tfo;
488 struct se_node_acl *se_nacl;
489 unsigned long flags;
490 bool drop_nacl = false;
491
492 if (!se_tpg) {
493 transport_free_session(se_sess);
494 return;
495 }
496 se_tfo = se_tpg->se_tpg_tfo;
497
498 spin_lock_irqsave(&se_tpg->session_lock, flags);
499 list_del(&se_sess->sess_list);
500 se_sess->se_tpg = NULL;
501 se_sess->fabric_sess_ptr = NULL;
502 spin_unlock_irqrestore(&se_tpg->session_lock, flags);
503
504 /*
505 * Determine if we need to do extra work for this initiator node's
506 * struct se_node_acl if it had been previously dynamically generated.
507 */
508 se_nacl = se_sess->se_node_acl;
509
510 mutex_lock(&se_tpg->acl_node_mutex);
511 if (se_nacl && se_nacl->dynamic_node_acl) {
512 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
513 list_del(&se_nacl->acl_list);
514 drop_nacl = true;
515 }
516 }
517 mutex_unlock(&se_tpg->acl_node_mutex);
518
519 if (drop_nacl) {
520 core_tpg_wait_for_nacl_pr_ref(se_nacl);
521 core_free_device_list_for_node(se_nacl, se_tpg);
522 se_sess->se_node_acl = NULL;
523 kfree(se_nacl);
524 }
525 pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
526 se_tpg->se_tpg_tfo->get_fabric_name());
527 /*
528 * If last kref is dropping now for an explicit NodeACL, awake sleeping
529 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
530 * removal context from within transport_free_session() code.
531 */
532
533 transport_free_session(se_sess);
534 }
535 EXPORT_SYMBOL(transport_deregister_session);
536
537 static void target_remove_from_state_list(struct se_cmd *cmd)
538 {
539 struct se_device *dev = cmd->se_dev;
540 unsigned long flags;
541
542 if (!dev)
543 return;
544
545 if (cmd->transport_state & CMD_T_BUSY)
546 return;
547
548 spin_lock_irqsave(&dev->execute_task_lock, flags);
549 if (cmd->state_active) {
550 list_del(&cmd->state_list);
551 cmd->state_active = false;
552 }
553 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
554 }
555
556 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
557 bool write_pending)
558 {
559 unsigned long flags;
560
561 if (remove_from_lists) {
562 target_remove_from_state_list(cmd);
563
564 /*
565 * Clear struct se_cmd->se_lun before the handoff to FE.
566 */
567 cmd->se_lun = NULL;
568 }
569
570 spin_lock_irqsave(&cmd->t_state_lock, flags);
571 if (write_pending)
572 cmd->t_state = TRANSPORT_WRITE_PENDING;
573
574 /*
575 * Determine if frontend context caller is requesting the stopping of
576 * this command for frontend exceptions.
577 */
578 if (cmd->transport_state & CMD_T_STOP) {
579 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
580 __func__, __LINE__, cmd->tag);
581
582 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
583
584 complete_all(&cmd->t_transport_stop_comp);
585 return 1;
586 }
587
588 cmd->transport_state &= ~CMD_T_ACTIVE;
589 if (remove_from_lists) {
590 /*
591 * Some fabric modules like tcm_loop can release
592 * their internally allocated I/O reference now and
593 * struct se_cmd now.
594 *
595 * Fabric modules are expected to return '1' here if the
596 * se_cmd being passed is released at this point,
597 * or zero if not being released.
598 */
599 if (cmd->se_tfo->check_stop_free != NULL) {
600 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
601 return cmd->se_tfo->check_stop_free(cmd);
602 }
603 }
604
605 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
606 return 0;
607 }
608
609 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
610 {
611 return transport_cmd_check_stop(cmd, true, false);
612 }
613
614 static void transport_lun_remove_cmd(struct se_cmd *cmd)
615 {
616 struct se_lun *lun = cmd->se_lun;
617
618 if (!lun)
619 return;
620
621 if (cmpxchg(&cmd->lun_ref_active, true, false))
622 percpu_ref_put(&lun->lun_ref);
623 }
624
625 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
626 {
627 bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
628
629 if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
630 transport_lun_remove_cmd(cmd);
631 /*
632 * Allow the fabric driver to unmap any resources before
633 * releasing the descriptor via TFO->release_cmd()
634 */
635 if (remove)
636 cmd->se_tfo->aborted_task(cmd);
637
638 if (transport_cmd_check_stop_to_fabric(cmd))
639 return;
640 if (remove && ack_kref)
641 transport_put_cmd(cmd);
642 }
643
644 static void target_complete_failure_work(struct work_struct *work)
645 {
646 struct se_cmd *cmd = container_of(work, struct se_cmd, work);
647
648 transport_generic_request_failure(cmd,
649 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
650 }
651
652 /*
653 * Used when asking transport to copy Sense Data from the underlying
654 * Linux/SCSI struct scsi_cmnd
655 */
656 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
657 {
658 struct se_device *dev = cmd->se_dev;
659
660 WARN_ON(!cmd->se_lun);
661
662 if (!dev)
663 return NULL;
664
665 if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
666 return NULL;
667
668 cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
669
670 pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
671 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
672 return cmd->sense_buffer;
673 }
674
675 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
676 {
677 struct se_device *dev = cmd->se_dev;
678 int success = scsi_status == GOOD;
679 unsigned long flags;
680
681 cmd->scsi_status = scsi_status;
682
683
684 spin_lock_irqsave(&cmd->t_state_lock, flags);
685 cmd->transport_state &= ~CMD_T_BUSY;
686
687 if (dev && dev->transport->transport_complete) {
688 dev->transport->transport_complete(cmd,
689 cmd->t_data_sg,
690 transport_get_sense_buffer(cmd));
691 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
692 success = 1;
693 }
694
695 /*
696 * See if we are waiting to complete for an exception condition.
697 */
698 if (cmd->transport_state & CMD_T_REQUEST_STOP) {
699 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
700 complete(&cmd->task_stop_comp);
701 return;
702 }
703
704 /*
705 * Check for case where an explicit ABORT_TASK has been received
706 * and transport_wait_for_tasks() will be waiting for completion..
707 */
708 if (cmd->transport_state & CMD_T_ABORTED ||
709 cmd->transport_state & CMD_T_STOP) {
710 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
711 complete_all(&cmd->t_transport_stop_comp);
712 return;
713 } else if (!success) {
714 INIT_WORK(&cmd->work, target_complete_failure_work);
715 } else {
716 INIT_WORK(&cmd->work, target_complete_ok_work);
717 }
718
719 cmd->t_state = TRANSPORT_COMPLETE;
720 cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
721 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
722
723 if (cmd->cpuid == -1)
724 queue_work(target_completion_wq, &cmd->work);
725 else
726 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
727 }
728 EXPORT_SYMBOL(target_complete_cmd);
729
730 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
731 {
732 if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
733 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
734 cmd->residual_count += cmd->data_length - length;
735 } else {
736 cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
737 cmd->residual_count = cmd->data_length - length;
738 }
739
740 cmd->data_length = length;
741 }
742
743 target_complete_cmd(cmd, scsi_status);
744 }
745 EXPORT_SYMBOL(target_complete_cmd_with_length);
746
747 static void target_add_to_state_list(struct se_cmd *cmd)
748 {
749 struct se_device *dev = cmd->se_dev;
750 unsigned long flags;
751
752 spin_lock_irqsave(&dev->execute_task_lock, flags);
753 if (!cmd->state_active) {
754 list_add_tail(&cmd->state_list, &dev->state_list);
755 cmd->state_active = true;
756 }
757 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
758 }
759
760 /*
761 * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
762 */
763 static void transport_write_pending_qf(struct se_cmd *cmd);
764 static void transport_complete_qf(struct se_cmd *cmd);
765
766 void target_qf_do_work(struct work_struct *work)
767 {
768 struct se_device *dev = container_of(work, struct se_device,
769 qf_work_queue);
770 LIST_HEAD(qf_cmd_list);
771 struct se_cmd *cmd, *cmd_tmp;
772
773 spin_lock_irq(&dev->qf_cmd_lock);
774 list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
775 spin_unlock_irq(&dev->qf_cmd_lock);
776
777 list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
778 list_del(&cmd->se_qf_node);
779 atomic_dec_mb(&dev->dev_qf_count);
780
781 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
782 " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
783 (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
784 (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
785 : "UNKNOWN");
786
787 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
788 transport_write_pending_qf(cmd);
789 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
790 transport_complete_qf(cmd);
791 }
792 }
793
794 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
795 {
796 switch (cmd->data_direction) {
797 case DMA_NONE:
798 return "NONE";
799 case DMA_FROM_DEVICE:
800 return "READ";
801 case DMA_TO_DEVICE:
802 return "WRITE";
803 case DMA_BIDIRECTIONAL:
804 return "BIDI";
805 default:
806 break;
807 }
808
809 return "UNKNOWN";
810 }
811
812 void transport_dump_dev_state(
813 struct se_device *dev,
814 char *b,
815 int *bl)
816 {
817 *bl += sprintf(b + *bl, "Status: ");
818 if (dev->export_count)
819 *bl += sprintf(b + *bl, "ACTIVATED");
820 else
821 *bl += sprintf(b + *bl, "DEACTIVATED");
822
823 *bl += sprintf(b + *bl, " Max Queue Depth: %d", dev->queue_depth);
824 *bl += sprintf(b + *bl, " SectorSize: %u HwMaxSectors: %u\n",
825 dev->dev_attrib.block_size,
826 dev->dev_attrib.hw_max_sectors);
827 *bl += sprintf(b + *bl, " ");
828 }
829
830 void transport_dump_vpd_proto_id(
831 struct t10_vpd *vpd,
832 unsigned char *p_buf,
833 int p_buf_len)
834 {
835 unsigned char buf[VPD_TMP_BUF_SIZE];
836 int len;
837
838 memset(buf, 0, VPD_TMP_BUF_SIZE);
839 len = sprintf(buf, "T10 VPD Protocol Identifier: ");
840
841 switch (vpd->protocol_identifier) {
842 case 0x00:
843 sprintf(buf+len, "Fibre Channel\n");
844 break;
845 case 0x10:
846 sprintf(buf+len, "Parallel SCSI\n");
847 break;
848 case 0x20:
849 sprintf(buf+len, "SSA\n");
850 break;
851 case 0x30:
852 sprintf(buf+len, "IEEE 1394\n");
853 break;
854 case 0x40:
855 sprintf(buf+len, "SCSI Remote Direct Memory Access"
856 " Protocol\n");
857 break;
858 case 0x50:
859 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
860 break;
861 case 0x60:
862 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
863 break;
864 case 0x70:
865 sprintf(buf+len, "Automation/Drive Interface Transport"
866 " Protocol\n");
867 break;
868 case 0x80:
869 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
870 break;
871 default:
872 sprintf(buf+len, "Unknown 0x%02x\n",
873 vpd->protocol_identifier);
874 break;
875 }
876
877 if (p_buf)
878 strncpy(p_buf, buf, p_buf_len);
879 else
880 pr_debug("%s", buf);
881 }
882
883 void
884 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
885 {
886 /*
887 * Check if the Protocol Identifier Valid (PIV) bit is set..
888 *
889 * from spc3r23.pdf section 7.5.1
890 */
891 if (page_83[1] & 0x80) {
892 vpd->protocol_identifier = (page_83[0] & 0xf0);
893 vpd->protocol_identifier_set = 1;
894 transport_dump_vpd_proto_id(vpd, NULL, 0);
895 }
896 }
897 EXPORT_SYMBOL(transport_set_vpd_proto_id);
898
899 int transport_dump_vpd_assoc(
900 struct t10_vpd *vpd,
901 unsigned char *p_buf,
902 int p_buf_len)
903 {
904 unsigned char buf[VPD_TMP_BUF_SIZE];
905 int ret = 0;
906 int len;
907
908 memset(buf, 0, VPD_TMP_BUF_SIZE);
909 len = sprintf(buf, "T10 VPD Identifier Association: ");
910
911 switch (vpd->association) {
912 case 0x00:
913 sprintf(buf+len, "addressed logical unit\n");
914 break;
915 case 0x10:
916 sprintf(buf+len, "target port\n");
917 break;
918 case 0x20:
919 sprintf(buf+len, "SCSI target device\n");
920 break;
921 default:
922 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
923 ret = -EINVAL;
924 break;
925 }
926
927 if (p_buf)
928 strncpy(p_buf, buf, p_buf_len);
929 else
930 pr_debug("%s", buf);
931
932 return ret;
933 }
934
935 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
936 {
937 /*
938 * The VPD identification association..
939 *
940 * from spc3r23.pdf Section 7.6.3.1 Table 297
941 */
942 vpd->association = (page_83[1] & 0x30);
943 return transport_dump_vpd_assoc(vpd, NULL, 0);
944 }
945 EXPORT_SYMBOL(transport_set_vpd_assoc);
946
947 int transport_dump_vpd_ident_type(
948 struct t10_vpd *vpd,
949 unsigned char *p_buf,
950 int p_buf_len)
951 {
952 unsigned char buf[VPD_TMP_BUF_SIZE];
953 int ret = 0;
954 int len;
955
956 memset(buf, 0, VPD_TMP_BUF_SIZE);
957 len = sprintf(buf, "T10 VPD Identifier Type: ");
958
959 switch (vpd->device_identifier_type) {
960 case 0x00:
961 sprintf(buf+len, "Vendor specific\n");
962 break;
963 case 0x01:
964 sprintf(buf+len, "T10 Vendor ID based\n");
965 break;
966 case 0x02:
967 sprintf(buf+len, "EUI-64 based\n");
968 break;
969 case 0x03:
970 sprintf(buf+len, "NAA\n");
971 break;
972 case 0x04:
973 sprintf(buf+len, "Relative target port identifier\n");
974 break;
975 case 0x08:
976 sprintf(buf+len, "SCSI name string\n");
977 break;
978 default:
979 sprintf(buf+len, "Unsupported: 0x%02x\n",
980 vpd->device_identifier_type);
981 ret = -EINVAL;
982 break;
983 }
984
985 if (p_buf) {
986 if (p_buf_len < strlen(buf)+1)
987 return -EINVAL;
988 strncpy(p_buf, buf, p_buf_len);
989 } else {
990 pr_debug("%s", buf);
991 }
992
993 return ret;
994 }
995
996 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
997 {
998 /*
999 * The VPD identifier type..
1000 *
1001 * from spc3r23.pdf Section 7.6.3.1 Table 298
1002 */
1003 vpd->device_identifier_type = (page_83[1] & 0x0f);
1004 return transport_dump_vpd_ident_type(vpd, NULL, 0);
1005 }
1006 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1007
1008 int transport_dump_vpd_ident(
1009 struct t10_vpd *vpd,
1010 unsigned char *p_buf,
1011 int p_buf_len)
1012 {
1013 unsigned char buf[VPD_TMP_BUF_SIZE];
1014 int ret = 0;
1015
1016 memset(buf, 0, VPD_TMP_BUF_SIZE);
1017
1018 switch (vpd->device_identifier_code_set) {
1019 case 0x01: /* Binary */
1020 snprintf(buf, sizeof(buf),
1021 "T10 VPD Binary Device Identifier: %s\n",
1022 &vpd->device_identifier[0]);
1023 break;
1024 case 0x02: /* ASCII */
1025 snprintf(buf, sizeof(buf),
1026 "T10 VPD ASCII Device Identifier: %s\n",
1027 &vpd->device_identifier[0]);
1028 break;
1029 case 0x03: /* UTF-8 */
1030 snprintf(buf, sizeof(buf),
1031 "T10 VPD UTF-8 Device Identifier: %s\n",
1032 &vpd->device_identifier[0]);
1033 break;
1034 default:
1035 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1036 " 0x%02x", vpd->device_identifier_code_set);
1037 ret = -EINVAL;
1038 break;
1039 }
1040
1041 if (p_buf)
1042 strncpy(p_buf, buf, p_buf_len);
1043 else
1044 pr_debug("%s", buf);
1045
1046 return ret;
1047 }
1048
1049 int
1050 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1051 {
1052 static const char hex_str[] = "0123456789abcdef";
1053 int j = 0, i = 4; /* offset to start of the identifier */
1054
1055 /*
1056 * The VPD Code Set (encoding)
1057 *
1058 * from spc3r23.pdf Section 7.6.3.1 Table 296
1059 */
1060 vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1061 switch (vpd->device_identifier_code_set) {
1062 case 0x01: /* Binary */
1063 vpd->device_identifier[j++] =
1064 hex_str[vpd->device_identifier_type];
1065 while (i < (4 + page_83[3])) {
1066 vpd->device_identifier[j++] =
1067 hex_str[(page_83[i] & 0xf0) >> 4];
1068 vpd->device_identifier[j++] =
1069 hex_str[page_83[i] & 0x0f];
1070 i++;
1071 }
1072 break;
1073 case 0x02: /* ASCII */
1074 case 0x03: /* UTF-8 */
1075 while (i < (4 + page_83[3]))
1076 vpd->device_identifier[j++] = page_83[i++];
1077 break;
1078 default:
1079 break;
1080 }
1081
1082 return transport_dump_vpd_ident(vpd, NULL, 0);
1083 }
1084 EXPORT_SYMBOL(transport_set_vpd_ident);
1085
1086 static sense_reason_t
1087 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1088 unsigned int size)
1089 {
1090 u32 mtl;
1091
1092 if (!cmd->se_tfo->max_data_sg_nents)
1093 return TCM_NO_SENSE;
1094 /*
1095 * Check if fabric enforced maximum SGL entries per I/O descriptor
1096 * exceeds se_cmd->data_length. If true, set SCF_UNDERFLOW_BIT +
1097 * residual_count and reduce original cmd->data_length to maximum
1098 * length based on single PAGE_SIZE entry scatter-lists.
1099 */
1100 mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1101 if (cmd->data_length > mtl) {
1102 /*
1103 * If an existing CDB overflow is present, calculate new residual
1104 * based on CDB size minus fabric maximum transfer length.
1105 *
1106 * If an existing CDB underflow is present, calculate new residual
1107 * based on original cmd->data_length minus fabric maximum transfer
1108 * length.
1109 *
1110 * Otherwise, set the underflow residual based on cmd->data_length
1111 * minus fabric maximum transfer length.
1112 */
1113 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1114 cmd->residual_count = (size - mtl);
1115 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1116 u32 orig_dl = size + cmd->residual_count;
1117 cmd->residual_count = (orig_dl - mtl);
1118 } else {
1119 cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1120 cmd->residual_count = (cmd->data_length - mtl);
1121 }
1122 cmd->data_length = mtl;
1123 /*
1124 * Reset sbc_check_prot() calculated protection payload
1125 * length based upon the new smaller MTL.
1126 */
1127 if (cmd->prot_length) {
1128 u32 sectors = (mtl / dev->dev_attrib.block_size);
1129 cmd->prot_length = dev->prot_length * sectors;
1130 }
1131 }
1132 return TCM_NO_SENSE;
1133 }
1134
1135 sense_reason_t
1136 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1137 {
1138 struct se_device *dev = cmd->se_dev;
1139
1140 if (cmd->unknown_data_length) {
1141 cmd->data_length = size;
1142 } else if (size != cmd->data_length) {
1143 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1144 " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1145 " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1146 cmd->data_length, size, cmd->t_task_cdb[0]);
1147
1148 if (cmd->data_direction == DMA_TO_DEVICE &&
1149 cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1150 pr_err("Rejecting underflow/overflow WRITE data\n");
1151 return TCM_INVALID_CDB_FIELD;
1152 }
1153 /*
1154 * Reject READ_* or WRITE_* with overflow/underflow for
1155 * type SCF_SCSI_DATA_CDB.
1156 */
1157 if (dev->dev_attrib.block_size != 512) {
1158 pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1159 " CDB on non 512-byte sector setup subsystem"
1160 " plugin: %s\n", dev->transport->name);
1161 /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1162 return TCM_INVALID_CDB_FIELD;
1163 }
1164 /*
1165 * For the overflow case keep the existing fabric provided
1166 * ->data_length. Otherwise for the underflow case, reset
1167 * ->data_length to the smaller SCSI expected data transfer
1168 * length.
1169 */
1170 if (size > cmd->data_length) {
1171 cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1172 cmd->residual_count = (size - cmd->data_length);
1173 } else {
1174 cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1175 cmd->residual_count = (cmd->data_length - size);
1176 cmd->data_length = size;
1177 }
1178 }
1179
1180 return target_check_max_data_sg_nents(cmd, dev, size);
1181
1182 }
1183
1184 /*
1185 * Used by fabric modules containing a local struct se_cmd within their
1186 * fabric dependent per I/O descriptor.
1187 *
1188 * Preserves the value of @cmd->tag.
1189 */
1190 void transport_init_se_cmd(
1191 struct se_cmd *cmd,
1192 const struct target_core_fabric_ops *tfo,
1193 struct se_session *se_sess,
1194 u32 data_length,
1195 int data_direction,
1196 int task_attr,
1197 unsigned char *sense_buffer)
1198 {
1199 INIT_LIST_HEAD(&cmd->se_delayed_node);
1200 INIT_LIST_HEAD(&cmd->se_qf_node);
1201 INIT_LIST_HEAD(&cmd->se_cmd_list);
1202 INIT_LIST_HEAD(&cmd->state_list);
1203 init_completion(&cmd->t_transport_stop_comp);
1204 init_completion(&cmd->cmd_wait_comp);
1205 init_completion(&cmd->task_stop_comp);
1206 spin_lock_init(&cmd->t_state_lock);
1207 kref_init(&cmd->cmd_kref);
1208 cmd->transport_state = CMD_T_DEV_ACTIVE;
1209
1210 cmd->se_tfo = tfo;
1211 cmd->se_sess = se_sess;
1212 cmd->data_length = data_length;
1213 cmd->data_direction = data_direction;
1214 cmd->sam_task_attr = task_attr;
1215 cmd->sense_buffer = sense_buffer;
1216
1217 cmd->state_active = false;
1218 }
1219 EXPORT_SYMBOL(transport_init_se_cmd);
1220
1221 static sense_reason_t
1222 transport_check_alloc_task_attr(struct se_cmd *cmd)
1223 {
1224 struct se_device *dev = cmd->se_dev;
1225
1226 /*
1227 * Check if SAM Task Attribute emulation is enabled for this
1228 * struct se_device storage object
1229 */
1230 if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1231 return 0;
1232
1233 if (cmd->sam_task_attr == TCM_ACA_TAG) {
1234 pr_debug("SAM Task Attribute ACA"
1235 " emulation is not supported\n");
1236 return TCM_INVALID_CDB_FIELD;
1237 }
1238
1239 return 0;
1240 }
1241
1242 sense_reason_t
1243 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1244 {
1245 struct se_device *dev = cmd->se_dev;
1246 sense_reason_t ret;
1247
1248 /*
1249 * Ensure that the received CDB is less than the max (252 + 8) bytes
1250 * for VARIABLE_LENGTH_CMD
1251 */
1252 if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1253 pr_err("Received SCSI CDB with command_size: %d that"
1254 " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1255 scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1256 return TCM_INVALID_CDB_FIELD;
1257 }
1258 /*
1259 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1260 * allocate the additional extended CDB buffer now.. Otherwise
1261 * setup the pointer from __t_task_cdb to t_task_cdb.
1262 */
1263 if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1264 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1265 GFP_KERNEL);
1266 if (!cmd->t_task_cdb) {
1267 pr_err("Unable to allocate cmd->t_task_cdb"
1268 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1269 scsi_command_size(cdb),
1270 (unsigned long)sizeof(cmd->__t_task_cdb));
1271 return TCM_OUT_OF_RESOURCES;
1272 }
1273 } else
1274 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1275 /*
1276 * Copy the original CDB into cmd->
1277 */
1278 memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1279
1280 trace_target_sequencer_start(cmd);
1281
1282 /*
1283 * Check for an existing UNIT ATTENTION condition
1284 */
1285 ret = target_scsi3_ua_check(cmd);
1286 if (ret)
1287 return ret;
1288
1289 ret = target_alua_state_check(cmd);
1290 if (ret)
1291 return ret;
1292
1293 ret = target_check_reservation(cmd);
1294 if (ret) {
1295 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1296 return ret;
1297 }
1298
1299 ret = dev->transport->parse_cdb(cmd);
1300 if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1301 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1302 cmd->se_tfo->get_fabric_name(),
1303 cmd->se_sess->se_node_acl->initiatorname,
1304 cmd->t_task_cdb[0]);
1305 if (ret)
1306 return ret;
1307
1308 ret = transport_check_alloc_task_attr(cmd);
1309 if (ret)
1310 return ret;
1311
1312 cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1313 atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1314 return 0;
1315 }
1316 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1317
1318 /*
1319 * Used by fabric module frontends to queue tasks directly.
1320 * May only be used from process context.
1321 */
1322 int transport_handle_cdb_direct(
1323 struct se_cmd *cmd)
1324 {
1325 sense_reason_t ret;
1326
1327 if (!cmd->se_lun) {
1328 dump_stack();
1329 pr_err("cmd->se_lun is NULL\n");
1330 return -EINVAL;
1331 }
1332 if (in_interrupt()) {
1333 dump_stack();
1334 pr_err("transport_generic_handle_cdb cannot be called"
1335 " from interrupt context\n");
1336 return -EINVAL;
1337 }
1338 /*
1339 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1340 * outstanding descriptors are handled correctly during shutdown via
1341 * transport_wait_for_tasks()
1342 *
1343 * Also, we don't take cmd->t_state_lock here as we only expect
1344 * this to be called for initial descriptor submission.
1345 */
1346 cmd->t_state = TRANSPORT_NEW_CMD;
1347 cmd->transport_state |= CMD_T_ACTIVE;
1348
1349 /*
1350 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1351 * so follow TRANSPORT_NEW_CMD processing thread context usage
1352 * and call transport_generic_request_failure() if necessary..
1353 */
1354 ret = transport_generic_new_cmd(cmd);
1355 if (ret)
1356 transport_generic_request_failure(cmd, ret);
1357 return 0;
1358 }
1359 EXPORT_SYMBOL(transport_handle_cdb_direct);
1360
1361 sense_reason_t
1362 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1363 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1364 {
1365 if (!sgl || !sgl_count)
1366 return 0;
1367
1368 /*
1369 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1370 * scatterlists already have been set to follow what the fabric
1371 * passes for the original expected data transfer length.
1372 */
1373 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1374 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1375 " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1376 return TCM_INVALID_CDB_FIELD;
1377 }
1378
1379 cmd->t_data_sg = sgl;
1380 cmd->t_data_nents = sgl_count;
1381 cmd->t_bidi_data_sg = sgl_bidi;
1382 cmd->t_bidi_data_nents = sgl_bidi_count;
1383
1384 cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1385 return 0;
1386 }
1387
1388 /*
1389 * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1390 * se_cmd + use pre-allocated SGL memory.
1391 *
1392 * @se_cmd: command descriptor to submit
1393 * @se_sess: associated se_sess for endpoint
1394 * @cdb: pointer to SCSI CDB
1395 * @sense: pointer to SCSI sense buffer
1396 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1397 * @data_length: fabric expected data transfer length
1398 * @task_addr: SAM task attribute
1399 * @data_dir: DMA data direction
1400 * @flags: flags for command submission from target_sc_flags_tables
1401 * @sgl: struct scatterlist memory for unidirectional mapping
1402 * @sgl_count: scatterlist count for unidirectional mapping
1403 * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1404 * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1405 * @sgl_prot: struct scatterlist memory protection information
1406 * @sgl_prot_count: scatterlist count for protection information
1407 *
1408 * Task tags are supported if the caller has set @se_cmd->tag.
1409 *
1410 * Returns non zero to signal active I/O shutdown failure. All other
1411 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1412 * but still return zero here.
1413 *
1414 * This may only be called from process context, and also currently
1415 * assumes internal allocation of fabric payload buffer by target-core.
1416 */
1417 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1418 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1419 u32 data_length, int task_attr, int data_dir, int flags,
1420 struct scatterlist *sgl, u32 sgl_count,
1421 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1422 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1423 {
1424 struct se_portal_group *se_tpg;
1425 sense_reason_t rc;
1426 int ret;
1427
1428 se_tpg = se_sess->se_tpg;
1429 BUG_ON(!se_tpg);
1430 BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1431 BUG_ON(in_interrupt());
1432 /*
1433 * Initialize se_cmd for target operation. From this point
1434 * exceptions are handled by sending exception status via
1435 * target_core_fabric_ops->queue_status() callback
1436 */
1437 transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1438 data_length, data_dir, task_attr, sense);
1439 if (flags & TARGET_SCF_UNKNOWN_SIZE)
1440 se_cmd->unknown_data_length = 1;
1441 /*
1442 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1443 * se_sess->sess_cmd_list. A second kref_get here is necessary
1444 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1445 * kref_put() to happen during fabric packet acknowledgement.
1446 */
1447 ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1448 if (ret)
1449 return ret;
1450 /*
1451 * Signal bidirectional data payloads to target-core
1452 */
1453 if (flags & TARGET_SCF_BIDI_OP)
1454 se_cmd->se_cmd_flags |= SCF_BIDI;
1455 /*
1456 * Locate se_lun pointer and attach it to struct se_cmd
1457 */
1458 rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1459 if (rc) {
1460 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1461 target_put_sess_cmd(se_cmd);
1462 return 0;
1463 }
1464
1465 rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1466 if (rc != 0) {
1467 transport_generic_request_failure(se_cmd, rc);
1468 return 0;
1469 }
1470
1471 /*
1472 * Save pointers for SGLs containing protection information,
1473 * if present.
1474 */
1475 if (sgl_prot_count) {
1476 se_cmd->t_prot_sg = sgl_prot;
1477 se_cmd->t_prot_nents = sgl_prot_count;
1478 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1479 }
1480
1481 /*
1482 * When a non zero sgl_count has been passed perform SGL passthrough
1483 * mapping for pre-allocated fabric memory instead of having target
1484 * core perform an internal SGL allocation..
1485 */
1486 if (sgl_count != 0) {
1487 BUG_ON(!sgl);
1488
1489 /*
1490 * A work-around for tcm_loop as some userspace code via
1491 * scsi-generic do not memset their associated read buffers,
1492 * so go ahead and do that here for type non-data CDBs. Also
1493 * note that this is currently guaranteed to be a single SGL
1494 * for this case by target core in target_setup_cmd_from_cdb()
1495 * -> transport_generic_cmd_sequencer().
1496 */
1497 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1498 se_cmd->data_direction == DMA_FROM_DEVICE) {
1499 unsigned char *buf = NULL;
1500
1501 if (sgl)
1502 buf = kmap(sg_page(sgl)) + sgl->offset;
1503
1504 if (buf) {
1505 memset(buf, 0, sgl->length);
1506 kunmap(sg_page(sgl));
1507 }
1508 }
1509
1510 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1511 sgl_bidi, sgl_bidi_count);
1512 if (rc != 0) {
1513 transport_generic_request_failure(se_cmd, rc);
1514 return 0;
1515 }
1516 }
1517
1518 /*
1519 * Check if we need to delay processing because of ALUA
1520 * Active/NonOptimized primary access state..
1521 */
1522 core_alua_check_nonop_delay(se_cmd);
1523
1524 transport_handle_cdb_direct(se_cmd);
1525 return 0;
1526 }
1527 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1528
1529 /*
1530 * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1531 *
1532 * @se_cmd: command descriptor to submit
1533 * @se_sess: associated se_sess for endpoint
1534 * @cdb: pointer to SCSI CDB
1535 * @sense: pointer to SCSI sense buffer
1536 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1537 * @data_length: fabric expected data transfer length
1538 * @task_addr: SAM task attribute
1539 * @data_dir: DMA data direction
1540 * @flags: flags for command submission from target_sc_flags_tables
1541 *
1542 * Task tags are supported if the caller has set @se_cmd->tag.
1543 *
1544 * Returns non zero to signal active I/O shutdown failure. All other
1545 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1546 * but still return zero here.
1547 *
1548 * This may only be called from process context, and also currently
1549 * assumes internal allocation of fabric payload buffer by target-core.
1550 *
1551 * It also assumes interal target core SGL memory allocation.
1552 */
1553 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1554 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1555 u32 data_length, int task_attr, int data_dir, int flags)
1556 {
1557 return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1558 unpacked_lun, data_length, task_attr, data_dir,
1559 flags, NULL, 0, NULL, 0, NULL, 0);
1560 }
1561 EXPORT_SYMBOL(target_submit_cmd);
1562
1563 static void target_complete_tmr_failure(struct work_struct *work)
1564 {
1565 struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1566
1567 se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1568 se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1569
1570 transport_cmd_check_stop_to_fabric(se_cmd);
1571 }
1572
1573 /**
1574 * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1575 * for TMR CDBs
1576 *
1577 * @se_cmd: command descriptor to submit
1578 * @se_sess: associated se_sess for endpoint
1579 * @sense: pointer to SCSI sense buffer
1580 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1581 * @fabric_context: fabric context for TMR req
1582 * @tm_type: Type of TM request
1583 * @gfp: gfp type for caller
1584 * @tag: referenced task tag for TMR_ABORT_TASK
1585 * @flags: submit cmd flags
1586 *
1587 * Callable from all contexts.
1588 **/
1589
1590 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1591 unsigned char *sense, u64 unpacked_lun,
1592 void *fabric_tmr_ptr, unsigned char tm_type,
1593 gfp_t gfp, u64 tag, int flags)
1594 {
1595 struct se_portal_group *se_tpg;
1596 int ret;
1597
1598 se_tpg = se_sess->se_tpg;
1599 BUG_ON(!se_tpg);
1600
1601 transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1602 0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1603 /*
1604 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1605 * allocation failure.
1606 */
1607 ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1608 if (ret < 0)
1609 return -ENOMEM;
1610
1611 if (tm_type == TMR_ABORT_TASK)
1612 se_cmd->se_tmr_req->ref_task_tag = tag;
1613
1614 /* See target_submit_cmd for commentary */
1615 ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1616 if (ret) {
1617 core_tmr_release_req(se_cmd->se_tmr_req);
1618 return ret;
1619 }
1620
1621 ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1622 if (ret) {
1623 /*
1624 * For callback during failure handling, push this work off
1625 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1626 */
1627 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1628 schedule_work(&se_cmd->work);
1629 return 0;
1630 }
1631 transport_generic_handle_tmr(se_cmd);
1632 return 0;
1633 }
1634 EXPORT_SYMBOL(target_submit_tmr);
1635
1636 /*
1637 * If the cmd is active, request it to be stopped and sleep until it
1638 * has completed.
1639 */
1640 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1641 __releases(&cmd->t_state_lock)
1642 __acquires(&cmd->t_state_lock)
1643 {
1644 bool was_active = false;
1645
1646 if (cmd->transport_state & CMD_T_BUSY) {
1647 cmd->transport_state |= CMD_T_REQUEST_STOP;
1648 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1649
1650 pr_debug("cmd %p waiting to complete\n", cmd);
1651 wait_for_completion(&cmd->task_stop_comp);
1652 pr_debug("cmd %p stopped successfully\n", cmd);
1653
1654 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1655 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1656 cmd->transport_state &= ~CMD_T_BUSY;
1657 was_active = true;
1658 }
1659
1660 return was_active;
1661 }
1662
1663 /*
1664 * Handle SAM-esque emulation for generic transport request failures.
1665 */
1666 void transport_generic_request_failure(struct se_cmd *cmd,
1667 sense_reason_t sense_reason)
1668 {
1669 int ret = 0, post_ret = 0;
1670
1671 pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1672 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1673 pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1674 cmd->se_tfo->get_cmd_state(cmd),
1675 cmd->t_state, sense_reason);
1676 pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1677 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1678 (cmd->transport_state & CMD_T_STOP) != 0,
1679 (cmd->transport_state & CMD_T_SENT) != 0);
1680
1681 /*
1682 * For SAM Task Attribute emulation for failed struct se_cmd
1683 */
1684 transport_complete_task_attr(cmd);
1685 /*
1686 * Handle special case for COMPARE_AND_WRITE failure, where the
1687 * callback is expected to drop the per device ->caw_sem.
1688 */
1689 if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1690 cmd->transport_complete_callback)
1691 cmd->transport_complete_callback(cmd, false, &post_ret);
1692
1693 switch (sense_reason) {
1694 case TCM_NON_EXISTENT_LUN:
1695 case TCM_UNSUPPORTED_SCSI_OPCODE:
1696 case TCM_INVALID_CDB_FIELD:
1697 case TCM_INVALID_PARAMETER_LIST:
1698 case TCM_PARAMETER_LIST_LENGTH_ERROR:
1699 case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1700 case TCM_UNKNOWN_MODE_PAGE:
1701 case TCM_WRITE_PROTECTED:
1702 case TCM_ADDRESS_OUT_OF_RANGE:
1703 case TCM_CHECK_CONDITION_ABORT_CMD:
1704 case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1705 case TCM_CHECK_CONDITION_NOT_READY:
1706 case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1707 case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1708 case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1709 break;
1710 case TCM_OUT_OF_RESOURCES:
1711 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1712 break;
1713 case TCM_RESERVATION_CONFLICT:
1714 /*
1715 * No SENSE Data payload for this case, set SCSI Status
1716 * and queue the response to $FABRIC_MOD.
1717 *
1718 * Uses linux/include/scsi/scsi.h SAM status codes defs
1719 */
1720 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1721 /*
1722 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1723 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1724 * CONFLICT STATUS.
1725 *
1726 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1727 */
1728 if (cmd->se_sess &&
1729 cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1730 target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1731 cmd->orig_fe_lun, 0x2C,
1732 ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1733 }
1734 trace_target_cmd_complete(cmd);
1735 ret = cmd->se_tfo->queue_status(cmd);
1736 if (ret == -EAGAIN || ret == -ENOMEM)
1737 goto queue_full;
1738 goto check_stop;
1739 default:
1740 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1741 cmd->t_task_cdb[0], sense_reason);
1742 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1743 break;
1744 }
1745
1746 ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1747 if (ret == -EAGAIN || ret == -ENOMEM)
1748 goto queue_full;
1749
1750 check_stop:
1751 transport_lun_remove_cmd(cmd);
1752 transport_cmd_check_stop_to_fabric(cmd);
1753 return;
1754
1755 queue_full:
1756 cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1757 transport_handle_queue_full(cmd, cmd->se_dev);
1758 }
1759 EXPORT_SYMBOL(transport_generic_request_failure);
1760
1761 void __target_execute_cmd(struct se_cmd *cmd)
1762 {
1763 sense_reason_t ret;
1764
1765 if (cmd->execute_cmd) {
1766 ret = cmd->execute_cmd(cmd);
1767 if (ret) {
1768 spin_lock_irq(&cmd->t_state_lock);
1769 cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1770 spin_unlock_irq(&cmd->t_state_lock);
1771
1772 transport_generic_request_failure(cmd, ret);
1773 }
1774 }
1775 }
1776
1777 static int target_write_prot_action(struct se_cmd *cmd)
1778 {
1779 u32 sectors;
1780 /*
1781 * Perform WRITE_INSERT of PI using software emulation when backend
1782 * device has PI enabled, if the transport has not already generated
1783 * PI using hardware WRITE_INSERT offload.
1784 */
1785 switch (cmd->prot_op) {
1786 case TARGET_PROT_DOUT_INSERT:
1787 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1788 sbc_dif_generate(cmd);
1789 break;
1790 case TARGET_PROT_DOUT_STRIP:
1791 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1792 break;
1793
1794 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1795 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1796 sectors, 0, cmd->t_prot_sg, 0);
1797 if (unlikely(cmd->pi_err)) {
1798 spin_lock_irq(&cmd->t_state_lock);
1799 cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1800 spin_unlock_irq(&cmd->t_state_lock);
1801 transport_generic_request_failure(cmd, cmd->pi_err);
1802 return -1;
1803 }
1804 break;
1805 default:
1806 break;
1807 }
1808
1809 return 0;
1810 }
1811
1812 static bool target_handle_task_attr(struct se_cmd *cmd)
1813 {
1814 struct se_device *dev = cmd->se_dev;
1815
1816 if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1817 return false;
1818
1819 /*
1820 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1821 * to allow the passed struct se_cmd list of tasks to the front of the list.
1822 */
1823 switch (cmd->sam_task_attr) {
1824 case TCM_HEAD_TAG:
1825 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1826 cmd->t_task_cdb[0]);
1827 return false;
1828 case TCM_ORDERED_TAG:
1829 atomic_inc_mb(&dev->dev_ordered_sync);
1830
1831 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1832 cmd->t_task_cdb[0]);
1833
1834 /*
1835 * Execute an ORDERED command if no other older commands
1836 * exist that need to be completed first.
1837 */
1838 if (!atomic_read(&dev->simple_cmds))
1839 return false;
1840 break;
1841 default:
1842 /*
1843 * For SIMPLE and UNTAGGED Task Attribute commands
1844 */
1845 atomic_inc_mb(&dev->simple_cmds);
1846 break;
1847 }
1848
1849 if (atomic_read(&dev->dev_ordered_sync) == 0)
1850 return false;
1851
1852 spin_lock(&dev->delayed_cmd_lock);
1853 list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1854 spin_unlock(&dev->delayed_cmd_lock);
1855
1856 pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1857 cmd->t_task_cdb[0], cmd->sam_task_attr);
1858 return true;
1859 }
1860
1861 void target_execute_cmd(struct se_cmd *cmd)
1862 {
1863 /*
1864 * If the received CDB has aleady been aborted stop processing it here.
1865 */
1866 if (transport_check_aborted_status(cmd, 1))
1867 return;
1868
1869 /*
1870 * Determine if frontend context caller is requesting the stopping of
1871 * this command for frontend exceptions.
1872 */
1873 spin_lock_irq(&cmd->t_state_lock);
1874 if (cmd->transport_state & CMD_T_STOP) {
1875 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1876 __func__, __LINE__, cmd->tag);
1877
1878 spin_unlock_irq(&cmd->t_state_lock);
1879 complete_all(&cmd->t_transport_stop_comp);
1880 return;
1881 }
1882
1883 cmd->t_state = TRANSPORT_PROCESSING;
1884 cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1885 spin_unlock_irq(&cmd->t_state_lock);
1886
1887 if (target_write_prot_action(cmd))
1888 return;
1889
1890 if (target_handle_task_attr(cmd)) {
1891 spin_lock_irq(&cmd->t_state_lock);
1892 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1893 spin_unlock_irq(&cmd->t_state_lock);
1894 return;
1895 }
1896
1897 __target_execute_cmd(cmd);
1898 }
1899 EXPORT_SYMBOL(target_execute_cmd);
1900
1901 /*
1902 * Process all commands up to the last received ORDERED task attribute which
1903 * requires another blocking boundary
1904 */
1905 static void target_restart_delayed_cmds(struct se_device *dev)
1906 {
1907 for (;;) {
1908 struct se_cmd *cmd;
1909
1910 spin_lock(&dev->delayed_cmd_lock);
1911 if (list_empty(&dev->delayed_cmd_list)) {
1912 spin_unlock(&dev->delayed_cmd_lock);
1913 break;
1914 }
1915
1916 cmd = list_entry(dev->delayed_cmd_list.next,
1917 struct se_cmd, se_delayed_node);
1918 list_del(&cmd->se_delayed_node);
1919 spin_unlock(&dev->delayed_cmd_lock);
1920
1921 __target_execute_cmd(cmd);
1922
1923 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1924 break;
1925 }
1926 }
1927
1928 /*
1929 * Called from I/O completion to determine which dormant/delayed
1930 * and ordered cmds need to have their tasks added to the execution queue.
1931 */
1932 static void transport_complete_task_attr(struct se_cmd *cmd)
1933 {
1934 struct se_device *dev = cmd->se_dev;
1935
1936 if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1937 return;
1938
1939 if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1940 atomic_dec_mb(&dev->simple_cmds);
1941 dev->dev_cur_ordered_id++;
1942 pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1943 dev->dev_cur_ordered_id);
1944 } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1945 dev->dev_cur_ordered_id++;
1946 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1947 dev->dev_cur_ordered_id);
1948 } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1949 atomic_dec_mb(&dev->dev_ordered_sync);
1950
1951 dev->dev_cur_ordered_id++;
1952 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1953 dev->dev_cur_ordered_id);
1954 }
1955
1956 target_restart_delayed_cmds(dev);
1957 }
1958
1959 static void transport_complete_qf(struct se_cmd *cmd)
1960 {
1961 int ret = 0;
1962
1963 transport_complete_task_attr(cmd);
1964
1965 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1966 trace_target_cmd_complete(cmd);
1967 ret = cmd->se_tfo->queue_status(cmd);
1968 goto out;
1969 }
1970
1971 switch (cmd->data_direction) {
1972 case DMA_FROM_DEVICE:
1973 trace_target_cmd_complete(cmd);
1974 ret = cmd->se_tfo->queue_data_in(cmd);
1975 break;
1976 case DMA_TO_DEVICE:
1977 if (cmd->se_cmd_flags & SCF_BIDI) {
1978 ret = cmd->se_tfo->queue_data_in(cmd);
1979 break;
1980 }
1981 /* Fall through for DMA_TO_DEVICE */
1982 case DMA_NONE:
1983 trace_target_cmd_complete(cmd);
1984 ret = cmd->se_tfo->queue_status(cmd);
1985 break;
1986 default:
1987 break;
1988 }
1989
1990 out:
1991 if (ret < 0) {
1992 transport_handle_queue_full(cmd, cmd->se_dev);
1993 return;
1994 }
1995 transport_lun_remove_cmd(cmd);
1996 transport_cmd_check_stop_to_fabric(cmd);
1997 }
1998
1999 static void transport_handle_queue_full(
2000 struct se_cmd *cmd,
2001 struct se_device *dev)
2002 {
2003 spin_lock_irq(&dev->qf_cmd_lock);
2004 list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2005 atomic_inc_mb(&dev->dev_qf_count);
2006 spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2007
2008 schedule_work(&cmd->se_dev->qf_work_queue);
2009 }
2010
2011 static bool target_read_prot_action(struct se_cmd *cmd)
2012 {
2013 switch (cmd->prot_op) {
2014 case TARGET_PROT_DIN_STRIP:
2015 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2016 u32 sectors = cmd->data_length >>
2017 ilog2(cmd->se_dev->dev_attrib.block_size);
2018
2019 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2020 sectors, 0, cmd->t_prot_sg,
2021 0);
2022 if (cmd->pi_err)
2023 return true;
2024 }
2025 break;
2026 case TARGET_PROT_DIN_INSERT:
2027 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2028 break;
2029
2030 sbc_dif_generate(cmd);
2031 break;
2032 default:
2033 break;
2034 }
2035
2036 return false;
2037 }
2038
2039 static void target_complete_ok_work(struct work_struct *work)
2040 {
2041 struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2042 int ret;
2043
2044 /*
2045 * Check if we need to move delayed/dormant tasks from cmds on the
2046 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2047 * Attribute.
2048 */
2049 transport_complete_task_attr(cmd);
2050
2051 /*
2052 * Check to schedule QUEUE_FULL work, or execute an existing
2053 * cmd->transport_qf_callback()
2054 */
2055 if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2056 schedule_work(&cmd->se_dev->qf_work_queue);
2057
2058 /*
2059 * Check if we need to send a sense buffer from
2060 * the struct se_cmd in question.
2061 */
2062 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2063 WARN_ON(!cmd->scsi_status);
2064 ret = transport_send_check_condition_and_sense(
2065 cmd, 0, 1);
2066 if (ret == -EAGAIN || ret == -ENOMEM)
2067 goto queue_full;
2068
2069 transport_lun_remove_cmd(cmd);
2070 transport_cmd_check_stop_to_fabric(cmd);
2071 return;
2072 }
2073 /*
2074 * Check for a callback, used by amongst other things
2075 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2076 */
2077 if (cmd->transport_complete_callback) {
2078 sense_reason_t rc;
2079 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2080 bool zero_dl = !(cmd->data_length);
2081 int post_ret = 0;
2082
2083 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2084 if (!rc && !post_ret) {
2085 if (caw && zero_dl)
2086 goto queue_rsp;
2087
2088 return;
2089 } else if (rc) {
2090 ret = transport_send_check_condition_and_sense(cmd,
2091 rc, 0);
2092 if (ret == -EAGAIN || ret == -ENOMEM)
2093 goto queue_full;
2094
2095 transport_lun_remove_cmd(cmd);
2096 transport_cmd_check_stop_to_fabric(cmd);
2097 return;
2098 }
2099 }
2100
2101 queue_rsp:
2102 switch (cmd->data_direction) {
2103 case DMA_FROM_DEVICE:
2104 atomic_long_add(cmd->data_length,
2105 &cmd->se_lun->lun_stats.tx_data_octets);
2106 /*
2107 * Perform READ_STRIP of PI using software emulation when
2108 * backend had PI enabled, if the transport will not be
2109 * performing hardware READ_STRIP offload.
2110 */
2111 if (target_read_prot_action(cmd)) {
2112 ret = transport_send_check_condition_and_sense(cmd,
2113 cmd->pi_err, 0);
2114 if (ret == -EAGAIN || ret == -ENOMEM)
2115 goto queue_full;
2116
2117 transport_lun_remove_cmd(cmd);
2118 transport_cmd_check_stop_to_fabric(cmd);
2119 return;
2120 }
2121
2122 trace_target_cmd_complete(cmd);
2123 ret = cmd->se_tfo->queue_data_in(cmd);
2124 if (ret == -EAGAIN || ret == -ENOMEM)
2125 goto queue_full;
2126 break;
2127 case DMA_TO_DEVICE:
2128 atomic_long_add(cmd->data_length,
2129 &cmd->se_lun->lun_stats.rx_data_octets);
2130 /*
2131 * Check if we need to send READ payload for BIDI-COMMAND
2132 */
2133 if (cmd->se_cmd_flags & SCF_BIDI) {
2134 atomic_long_add(cmd->data_length,
2135 &cmd->se_lun->lun_stats.tx_data_octets);
2136 ret = cmd->se_tfo->queue_data_in(cmd);
2137 if (ret == -EAGAIN || ret == -ENOMEM)
2138 goto queue_full;
2139 break;
2140 }
2141 /* Fall through for DMA_TO_DEVICE */
2142 case DMA_NONE:
2143 trace_target_cmd_complete(cmd);
2144 ret = cmd->se_tfo->queue_status(cmd);
2145 if (ret == -EAGAIN || ret == -ENOMEM)
2146 goto queue_full;
2147 break;
2148 default:
2149 break;
2150 }
2151
2152 transport_lun_remove_cmd(cmd);
2153 transport_cmd_check_stop_to_fabric(cmd);
2154 return;
2155
2156 queue_full:
2157 pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2158 " data_direction: %d\n", cmd, cmd->data_direction);
2159 cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2160 transport_handle_queue_full(cmd, cmd->se_dev);
2161 }
2162
2163 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2164 {
2165 struct scatterlist *sg;
2166 int count;
2167
2168 for_each_sg(sgl, sg, nents, count)
2169 __free_page(sg_page(sg));
2170
2171 kfree(sgl);
2172 }
2173
2174 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2175 {
2176 /*
2177 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2178 * emulation, and free + reset pointers if necessary..
2179 */
2180 if (!cmd->t_data_sg_orig)
2181 return;
2182
2183 kfree(cmd->t_data_sg);
2184 cmd->t_data_sg = cmd->t_data_sg_orig;
2185 cmd->t_data_sg_orig = NULL;
2186 cmd->t_data_nents = cmd->t_data_nents_orig;
2187 cmd->t_data_nents_orig = 0;
2188 }
2189
2190 static inline void transport_free_pages(struct se_cmd *cmd)
2191 {
2192 if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2193 transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2194 cmd->t_prot_sg = NULL;
2195 cmd->t_prot_nents = 0;
2196 }
2197
2198 if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2199 /*
2200 * Release special case READ buffer payload required for
2201 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2202 */
2203 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2204 transport_free_sgl(cmd->t_bidi_data_sg,
2205 cmd->t_bidi_data_nents);
2206 cmd->t_bidi_data_sg = NULL;
2207 cmd->t_bidi_data_nents = 0;
2208 }
2209 transport_reset_sgl_orig(cmd);
2210 return;
2211 }
2212 transport_reset_sgl_orig(cmd);
2213
2214 transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2215 cmd->t_data_sg = NULL;
2216 cmd->t_data_nents = 0;
2217
2218 transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2219 cmd->t_bidi_data_sg = NULL;
2220 cmd->t_bidi_data_nents = 0;
2221 }
2222
2223 /**
2224 * transport_put_cmd - release a reference to a command
2225 * @cmd: command to release
2226 *
2227 * This routine releases our reference to the command and frees it if possible.
2228 */
2229 static int transport_put_cmd(struct se_cmd *cmd)
2230 {
2231 BUG_ON(!cmd->se_tfo);
2232 /*
2233 * If this cmd has been setup with target_get_sess_cmd(), drop
2234 * the kref and call ->release_cmd() in kref callback.
2235 */
2236 return target_put_sess_cmd(cmd);
2237 }
2238
2239 void *transport_kmap_data_sg(struct se_cmd *cmd)
2240 {
2241 struct scatterlist *sg = cmd->t_data_sg;
2242 struct page **pages;
2243 int i;
2244
2245 /*
2246 * We need to take into account a possible offset here for fabrics like
2247 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2248 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2249 */
2250 if (!cmd->t_data_nents)
2251 return NULL;
2252
2253 BUG_ON(!sg);
2254 if (cmd->t_data_nents == 1)
2255 return kmap(sg_page(sg)) + sg->offset;
2256
2257 /* >1 page. use vmap */
2258 pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2259 if (!pages)
2260 return NULL;
2261
2262 /* convert sg[] to pages[] */
2263 for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2264 pages[i] = sg_page(sg);
2265 }
2266
2267 cmd->t_data_vmap = vmap(pages, cmd->t_data_nents, VM_MAP, PAGE_KERNEL);
2268 kfree(pages);
2269 if (!cmd->t_data_vmap)
2270 return NULL;
2271
2272 return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2273 }
2274 EXPORT_SYMBOL(transport_kmap_data_sg);
2275
2276 void transport_kunmap_data_sg(struct se_cmd *cmd)
2277 {
2278 if (!cmd->t_data_nents) {
2279 return;
2280 } else if (cmd->t_data_nents == 1) {
2281 kunmap(sg_page(cmd->t_data_sg));
2282 return;
2283 }
2284
2285 vunmap(cmd->t_data_vmap);
2286 cmd->t_data_vmap = NULL;
2287 }
2288 EXPORT_SYMBOL(transport_kunmap_data_sg);
2289
2290 int
2291 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2292 bool zero_page)
2293 {
2294 struct scatterlist *sg;
2295 struct page *page;
2296 gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2297 unsigned int nent;
2298 int i = 0;
2299
2300 nent = DIV_ROUND_UP(length, PAGE_SIZE);
2301 sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2302 if (!sg)
2303 return -ENOMEM;
2304
2305 sg_init_table(sg, nent);
2306
2307 while (length) {
2308 u32 page_len = min_t(u32, length, PAGE_SIZE);
2309 page = alloc_page(GFP_KERNEL | zero_flag);
2310 if (!page)
2311 goto out;
2312
2313 sg_set_page(&sg[i], page, page_len, 0);
2314 length -= page_len;
2315 i++;
2316 }
2317 *sgl = sg;
2318 *nents = nent;
2319 return 0;
2320
2321 out:
2322 while (i > 0) {
2323 i--;
2324 __free_page(sg_page(&sg[i]));
2325 }
2326 kfree(sg);
2327 return -ENOMEM;
2328 }
2329
2330 /*
2331 * Allocate any required resources to execute the command. For writes we
2332 * might not have the payload yet, so notify the fabric via a call to
2333 * ->write_pending instead. Otherwise place it on the execution queue.
2334 */
2335 sense_reason_t
2336 transport_generic_new_cmd(struct se_cmd *cmd)
2337 {
2338 int ret = 0;
2339 bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2340
2341 if (cmd->prot_op != TARGET_PROT_NORMAL &&
2342 !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2343 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2344 cmd->prot_length, true);
2345 if (ret < 0)
2346 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2347 }
2348
2349 /*
2350 * Determine is the TCM fabric module has already allocated physical
2351 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2352 * beforehand.
2353 */
2354 if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2355 cmd->data_length) {
2356
2357 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2358 (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2359 u32 bidi_length;
2360
2361 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2362 bidi_length = cmd->t_task_nolb *
2363 cmd->se_dev->dev_attrib.block_size;
2364 else
2365 bidi_length = cmd->data_length;
2366
2367 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2368 &cmd->t_bidi_data_nents,
2369 bidi_length, zero_flag);
2370 if (ret < 0)
2371 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2372 }
2373
2374 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2375 cmd->data_length, zero_flag);
2376 if (ret < 0)
2377 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2378 } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2379 cmd->data_length) {
2380 /*
2381 * Special case for COMPARE_AND_WRITE with fabrics
2382 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2383 */
2384 u32 caw_length = cmd->t_task_nolb *
2385 cmd->se_dev->dev_attrib.block_size;
2386
2387 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2388 &cmd->t_bidi_data_nents,
2389 caw_length, zero_flag);
2390 if (ret < 0)
2391 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2392 }
2393 /*
2394 * If this command is not a write we can execute it right here,
2395 * for write buffers we need to notify the fabric driver first
2396 * and let it call back once the write buffers are ready.
2397 */
2398 target_add_to_state_list(cmd);
2399 if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2400 target_execute_cmd(cmd);
2401 return 0;
2402 }
2403 transport_cmd_check_stop(cmd, false, true);
2404
2405 ret = cmd->se_tfo->write_pending(cmd);
2406 if (ret == -EAGAIN || ret == -ENOMEM)
2407 goto queue_full;
2408
2409 /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2410 WARN_ON(ret);
2411
2412 return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2413
2414 queue_full:
2415 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2416 cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2417 transport_handle_queue_full(cmd, cmd->se_dev);
2418 return 0;
2419 }
2420 EXPORT_SYMBOL(transport_generic_new_cmd);
2421
2422 static void transport_write_pending_qf(struct se_cmd *cmd)
2423 {
2424 int ret;
2425
2426 ret = cmd->se_tfo->write_pending(cmd);
2427 if (ret == -EAGAIN || ret == -ENOMEM) {
2428 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2429 cmd);
2430 transport_handle_queue_full(cmd, cmd->se_dev);
2431 }
2432 }
2433
2434 static bool
2435 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2436 unsigned long *flags);
2437
2438 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2439 {
2440 unsigned long flags;
2441
2442 spin_lock_irqsave(&cmd->t_state_lock, flags);
2443 __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2444 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2445 }
2446
2447 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2448 {
2449 int ret = 0;
2450 bool aborted = false, tas = false;
2451
2452 if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2453 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2454 target_wait_free_cmd(cmd, &aborted, &tas);
2455
2456 if (!aborted || tas)
2457 ret = transport_put_cmd(cmd);
2458 } else {
2459 if (wait_for_tasks)
2460 target_wait_free_cmd(cmd, &aborted, &tas);
2461 /*
2462 * Handle WRITE failure case where transport_generic_new_cmd()
2463 * has already added se_cmd to state_list, but fabric has
2464 * failed command before I/O submission.
2465 */
2466 if (cmd->state_active)
2467 target_remove_from_state_list(cmd);
2468
2469 if (cmd->se_lun)
2470 transport_lun_remove_cmd(cmd);
2471
2472 if (!aborted || tas)
2473 ret = transport_put_cmd(cmd);
2474 }
2475 /*
2476 * If the task has been internally aborted due to TMR ABORT_TASK
2477 * or LUN_RESET, target_core_tmr.c is responsible for performing
2478 * the remaining calls to target_put_sess_cmd(), and not the
2479 * callers of this function.
2480 */
2481 if (aborted) {
2482 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2483 wait_for_completion(&cmd->cmd_wait_comp);
2484 cmd->se_tfo->release_cmd(cmd);
2485 ret = 1;
2486 }
2487 return ret;
2488 }
2489 EXPORT_SYMBOL(transport_generic_free_cmd);
2490
2491 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2492 * @se_cmd: command descriptor to add
2493 * @ack_kref: Signal that fabric will perform an ack target_put_sess_cmd()
2494 */
2495 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2496 {
2497 struct se_session *se_sess = se_cmd->se_sess;
2498 unsigned long flags;
2499 int ret = 0;
2500
2501 /*
2502 * Add a second kref if the fabric caller is expecting to handle
2503 * fabric acknowledgement that requires two target_put_sess_cmd()
2504 * invocations before se_cmd descriptor release.
2505 */
2506 if (ack_kref)
2507 kref_get(&se_cmd->cmd_kref);
2508
2509 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2510 if (se_sess->sess_tearing_down) {
2511 ret = -ESHUTDOWN;
2512 goto out;
2513 }
2514 list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2515 out:
2516 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2517
2518 if (ret && ack_kref)
2519 target_put_sess_cmd(se_cmd);
2520
2521 return ret;
2522 }
2523 EXPORT_SYMBOL(target_get_sess_cmd);
2524
2525 static void target_free_cmd_mem(struct se_cmd *cmd)
2526 {
2527 transport_free_pages(cmd);
2528
2529 if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2530 core_tmr_release_req(cmd->se_tmr_req);
2531 if (cmd->t_task_cdb != cmd->__t_task_cdb)
2532 kfree(cmd->t_task_cdb);
2533 }
2534
2535 static void target_release_cmd_kref(struct kref *kref)
2536 {
2537 struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2538 struct se_session *se_sess = se_cmd->se_sess;
2539 unsigned long flags;
2540 bool fabric_stop;
2541
2542 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2543 if (list_empty(&se_cmd->se_cmd_list)) {
2544 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2545 target_free_cmd_mem(se_cmd);
2546 se_cmd->se_tfo->release_cmd(se_cmd);
2547 return;
2548 }
2549
2550 spin_lock(&se_cmd->t_state_lock);
2551 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP);
2552 spin_unlock(&se_cmd->t_state_lock);
2553
2554 if (se_cmd->cmd_wait_set || fabric_stop) {
2555 list_del_init(&se_cmd->se_cmd_list);
2556 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2557 target_free_cmd_mem(se_cmd);
2558 complete(&se_cmd->cmd_wait_comp);
2559 return;
2560 }
2561 list_del_init(&se_cmd->se_cmd_list);
2562 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2563
2564 target_free_cmd_mem(se_cmd);
2565 se_cmd->se_tfo->release_cmd(se_cmd);
2566 }
2567
2568 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2569 * @se_cmd: command descriptor to drop
2570 */
2571 int target_put_sess_cmd(struct se_cmd *se_cmd)
2572 {
2573 struct se_session *se_sess = se_cmd->se_sess;
2574
2575 if (!se_sess) {
2576 target_free_cmd_mem(se_cmd);
2577 se_cmd->se_tfo->release_cmd(se_cmd);
2578 return 1;
2579 }
2580 return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2581 }
2582 EXPORT_SYMBOL(target_put_sess_cmd);
2583
2584 /* target_sess_cmd_list_set_waiting - Flag all commands in
2585 * sess_cmd_list to complete cmd_wait_comp. Set
2586 * sess_tearing_down so no more commands are queued.
2587 * @se_sess: session to flag
2588 */
2589 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2590 {
2591 struct se_cmd *se_cmd;
2592 unsigned long flags;
2593 int rc;
2594
2595 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2596 if (se_sess->sess_tearing_down) {
2597 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2598 return;
2599 }
2600 se_sess->sess_tearing_down = 1;
2601 list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2602
2603 list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) {
2604 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2605 if (rc) {
2606 se_cmd->cmd_wait_set = 1;
2607 spin_lock(&se_cmd->t_state_lock);
2608 se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2609 spin_unlock(&se_cmd->t_state_lock);
2610 }
2611 }
2612
2613 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2614 }
2615 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2616
2617 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2618 * @se_sess: session to wait for active I/O
2619 */
2620 void target_wait_for_sess_cmds(struct se_session *se_sess)
2621 {
2622 struct se_cmd *se_cmd, *tmp_cmd;
2623 unsigned long flags;
2624 bool tas;
2625
2626 list_for_each_entry_safe(se_cmd, tmp_cmd,
2627 &se_sess->sess_wait_list, se_cmd_list) {
2628 list_del_init(&se_cmd->se_cmd_list);
2629
2630 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2631 " %d\n", se_cmd, se_cmd->t_state,
2632 se_cmd->se_tfo->get_cmd_state(se_cmd));
2633
2634 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2635 tas = (se_cmd->transport_state & CMD_T_TAS);
2636 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2637
2638 if (!target_put_sess_cmd(se_cmd)) {
2639 if (tas)
2640 target_put_sess_cmd(se_cmd);
2641 }
2642
2643 wait_for_completion(&se_cmd->cmd_wait_comp);
2644 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2645 " fabric state: %d\n", se_cmd, se_cmd->t_state,
2646 se_cmd->se_tfo->get_cmd_state(se_cmd));
2647
2648 se_cmd->se_tfo->release_cmd(se_cmd);
2649 }
2650
2651 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2652 WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2653 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2654
2655 }
2656 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2657
2658 void transport_clear_lun_ref(struct se_lun *lun)
2659 {
2660 percpu_ref_kill(&lun->lun_ref);
2661 wait_for_completion(&lun->lun_ref_comp);
2662 }
2663
2664 static bool
2665 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2666 bool *aborted, bool *tas, unsigned long *flags)
2667 __releases(&cmd->t_state_lock)
2668 __acquires(&cmd->t_state_lock)
2669 {
2670
2671 assert_spin_locked(&cmd->t_state_lock);
2672 WARN_ON_ONCE(!irqs_disabled());
2673
2674 if (fabric_stop)
2675 cmd->transport_state |= CMD_T_FABRIC_STOP;
2676
2677 if (cmd->transport_state & CMD_T_ABORTED)
2678 *aborted = true;
2679
2680 if (cmd->transport_state & CMD_T_TAS)
2681 *tas = true;
2682
2683 if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2684 !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2685 return false;
2686
2687 if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2688 !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2689 return false;
2690
2691 if (!(cmd->transport_state & CMD_T_ACTIVE))
2692 return false;
2693
2694 if (fabric_stop && *aborted)
2695 return false;
2696
2697 cmd->transport_state |= CMD_T_STOP;
2698
2699 pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2700 " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2701 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2702
2703 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2704
2705 wait_for_completion(&cmd->t_transport_stop_comp);
2706
2707 spin_lock_irqsave(&cmd->t_state_lock, *flags);
2708 cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2709
2710 pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2711 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2712
2713 return true;
2714 }
2715
2716 /**
2717 * transport_wait_for_tasks - wait for completion to occur
2718 * @cmd: command to wait
2719 *
2720 * Called from frontend fabric context to wait for storage engine
2721 * to pause and/or release frontend generated struct se_cmd.
2722 */
2723 bool transport_wait_for_tasks(struct se_cmd *cmd)
2724 {
2725 unsigned long flags;
2726 bool ret, aborted = false, tas = false;
2727
2728 spin_lock_irqsave(&cmd->t_state_lock, flags);
2729 ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2730 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2731
2732 return ret;
2733 }
2734 EXPORT_SYMBOL(transport_wait_for_tasks);
2735
2736 struct sense_info {
2737 u8 key;
2738 u8 asc;
2739 u8 ascq;
2740 bool add_sector_info;
2741 };
2742
2743 static const struct sense_info sense_info_table[] = {
2744 [TCM_NO_SENSE] = {
2745 .key = NOT_READY
2746 },
2747 [TCM_NON_EXISTENT_LUN] = {
2748 .key = ILLEGAL_REQUEST,
2749 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2750 },
2751 [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2752 .key = ILLEGAL_REQUEST,
2753 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2754 },
2755 [TCM_SECTOR_COUNT_TOO_MANY] = {
2756 .key = ILLEGAL_REQUEST,
2757 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2758 },
2759 [TCM_UNKNOWN_MODE_PAGE] = {
2760 .key = ILLEGAL_REQUEST,
2761 .asc = 0x24, /* INVALID FIELD IN CDB */
2762 },
2763 [TCM_CHECK_CONDITION_ABORT_CMD] = {
2764 .key = ABORTED_COMMAND,
2765 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2766 .ascq = 0x03,
2767 },
2768 [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2769 .key = ABORTED_COMMAND,
2770 .asc = 0x0c, /* WRITE ERROR */
2771 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2772 },
2773 [TCM_INVALID_CDB_FIELD] = {
2774 .key = ILLEGAL_REQUEST,
2775 .asc = 0x24, /* INVALID FIELD IN CDB */
2776 },
2777 [TCM_INVALID_PARAMETER_LIST] = {
2778 .key = ILLEGAL_REQUEST,
2779 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2780 },
2781 [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2782 .key = ILLEGAL_REQUEST,
2783 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2784 },
2785 [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2786 .key = ILLEGAL_REQUEST,
2787 .asc = 0x0c, /* WRITE ERROR */
2788 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2789 },
2790 [TCM_SERVICE_CRC_ERROR] = {
2791 .key = ABORTED_COMMAND,
2792 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2793 .ascq = 0x05, /* N/A */
2794 },
2795 [TCM_SNACK_REJECTED] = {
2796 .key = ABORTED_COMMAND,
2797 .asc = 0x11, /* READ ERROR */
2798 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2799 },
2800 [TCM_WRITE_PROTECTED] = {
2801 .key = DATA_PROTECT,
2802 .asc = 0x27, /* WRITE PROTECTED */
2803 },
2804 [TCM_ADDRESS_OUT_OF_RANGE] = {
2805 .key = ILLEGAL_REQUEST,
2806 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2807 },
2808 [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2809 .key = UNIT_ATTENTION,
2810 },
2811 [TCM_CHECK_CONDITION_NOT_READY] = {
2812 .key = NOT_READY,
2813 },
2814 [TCM_MISCOMPARE_VERIFY] = {
2815 .key = MISCOMPARE,
2816 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2817 .ascq = 0x00,
2818 },
2819 [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2820 .key = ABORTED_COMMAND,
2821 .asc = 0x10,
2822 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2823 .add_sector_info = true,
2824 },
2825 [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2826 .key = ABORTED_COMMAND,
2827 .asc = 0x10,
2828 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2829 .add_sector_info = true,
2830 },
2831 [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2832 .key = ABORTED_COMMAND,
2833 .asc = 0x10,
2834 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2835 .add_sector_info = true,
2836 },
2837 [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2838 /*
2839 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2840 * Solaris initiators. Returning NOT READY instead means the
2841 * operations will be retried a finite number of times and we
2842 * can survive intermittent errors.
2843 */
2844 .key = NOT_READY,
2845 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2846 },
2847 };
2848
2849 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2850 {
2851 const struct sense_info *si;
2852 u8 *buffer = cmd->sense_buffer;
2853 int r = (__force int)reason;
2854 u8 asc, ascq;
2855 bool desc_format = target_sense_desc_format(cmd->se_dev);
2856
2857 if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2858 si = &sense_info_table[r];
2859 else
2860 si = &sense_info_table[(__force int)
2861 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2862
2863 if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2864 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2865 WARN_ON_ONCE(asc == 0);
2866 } else if (si->asc == 0) {
2867 WARN_ON_ONCE(cmd->scsi_asc == 0);
2868 asc = cmd->scsi_asc;
2869 ascq = cmd->scsi_ascq;
2870 } else {
2871 asc = si->asc;
2872 ascq = si->ascq;
2873 }
2874
2875 scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2876 if (si->add_sector_info)
2877 return scsi_set_sense_information(buffer,
2878 cmd->scsi_sense_length,
2879 cmd->bad_sector);
2880
2881 return 0;
2882 }
2883
2884 int
2885 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2886 sense_reason_t reason, int from_transport)
2887 {
2888 unsigned long flags;
2889
2890 spin_lock_irqsave(&cmd->t_state_lock, flags);
2891 if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2892 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2893 return 0;
2894 }
2895 cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2896 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2897
2898 if (!from_transport) {
2899 int rc;
2900
2901 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2902 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2903 cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
2904 rc = translate_sense_reason(cmd, reason);
2905 if (rc)
2906 return rc;
2907 }
2908
2909 trace_target_cmd_complete(cmd);
2910 return cmd->se_tfo->queue_status(cmd);
2911 }
2912 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2913
2914 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2915 {
2916 if (!(cmd->transport_state & CMD_T_ABORTED))
2917 return 0;
2918
2919 /*
2920 * If cmd has been aborted but either no status is to be sent or it has
2921 * already been sent, just return
2922 */
2923 if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2924 return 1;
2925
2926 pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08llx\n",
2927 cmd->t_task_cdb[0], cmd->tag);
2928
2929 cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2930 cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2931 trace_target_cmd_complete(cmd);
2932 cmd->se_tfo->queue_status(cmd);
2933
2934 return 1;
2935 }
2936 EXPORT_SYMBOL(transport_check_aborted_status);
2937
2938 void transport_send_task_abort(struct se_cmd *cmd)
2939 {
2940 unsigned long flags;
2941
2942 spin_lock_irqsave(&cmd->t_state_lock, flags);
2943 if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2944 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2945 return;
2946 }
2947 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2948
2949 /*
2950 * If there are still expected incoming fabric WRITEs, we wait
2951 * until until they have completed before sending a TASK_ABORTED
2952 * response. This response with TASK_ABORTED status will be
2953 * queued back to fabric module by transport_check_aborted_status().
2954 */
2955 if (cmd->data_direction == DMA_TO_DEVICE) {
2956 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2957 cmd->transport_state |= CMD_T_ABORTED;
2958 cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2959 return;
2960 }
2961 }
2962 cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2963
2964 transport_lun_remove_cmd(cmd);
2965
2966 pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
2967 cmd->t_task_cdb[0], cmd->tag);
2968
2969 trace_target_cmd_complete(cmd);
2970 cmd->se_tfo->queue_status(cmd);
2971 }
2972
2973 static void target_tmr_work(struct work_struct *work)
2974 {
2975 struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2976 struct se_device *dev = cmd->se_dev;
2977 struct se_tmr_req *tmr = cmd->se_tmr_req;
2978 unsigned long flags;
2979 int ret;
2980
2981 spin_lock_irqsave(&cmd->t_state_lock, flags);
2982 if (cmd->transport_state & CMD_T_ABORTED) {
2983 tmr->response = TMR_FUNCTION_REJECTED;
2984 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2985 goto check_stop;
2986 }
2987 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2988
2989 switch (tmr->function) {
2990 case TMR_ABORT_TASK:
2991 core_tmr_abort_task(dev, tmr, cmd->se_sess);
2992 break;
2993 case TMR_ABORT_TASK_SET:
2994 case TMR_CLEAR_ACA:
2995 case TMR_CLEAR_TASK_SET:
2996 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2997 break;
2998 case TMR_LUN_RESET:
2999 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3000 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3001 TMR_FUNCTION_REJECTED;
3002 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3003 target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3004 cmd->orig_fe_lun, 0x29,
3005 ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3006 }
3007 break;
3008 case TMR_TARGET_WARM_RESET:
3009 tmr->response = TMR_FUNCTION_REJECTED;
3010 break;
3011 case TMR_TARGET_COLD_RESET:
3012 tmr->response = TMR_FUNCTION_REJECTED;
3013 break;
3014 default:
3015 pr_err("Uknown TMR function: 0x%02x.\n",
3016 tmr->function);
3017 tmr->response = TMR_FUNCTION_REJECTED;
3018 break;
3019 }
3020
3021 spin_lock_irqsave(&cmd->t_state_lock, flags);
3022 if (cmd->transport_state & CMD_T_ABORTED) {
3023 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3024 goto check_stop;
3025 }
3026 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3027 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3028
3029 cmd->se_tfo->queue_tm_rsp(cmd);
3030
3031 check_stop:
3032 transport_cmd_check_stop_to_fabric(cmd);
3033 }
3034
3035 int transport_generic_handle_tmr(
3036 struct se_cmd *cmd)
3037 {
3038 unsigned long flags;
3039
3040 spin_lock_irqsave(&cmd->t_state_lock, flags);
3041 cmd->transport_state |= CMD_T_ACTIVE;
3042 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3043
3044 INIT_WORK(&cmd->work, target_tmr_work);
3045 queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3046 return 0;
3047 }
3048 EXPORT_SYMBOL(transport_generic_handle_tmr);
3049
3050 bool
3051 target_check_wce(struct se_device *dev)
3052 {
3053 bool wce = false;
3054
3055 if (dev->transport->get_write_cache)
3056 wce = dev->transport->get_write_cache(dev);
3057 else if (dev->dev_attrib.emulate_write_cache > 0)
3058 wce = true;
3059
3060 return wce;
3061 }
3062
3063 bool
3064 target_check_fua(struct se_device *dev)
3065 {
3066 return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3067 }
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